SolrNet, the C# client for Apache Solr, has a new release: 0.5.1. The current release aims to include a breaking change with the latest versions of Solr 4.x in which multiple collations are returned by Solr. I am currently working on getting it to Nuget

This is the release:

SolrNet Release 0.5.1: Fix Spellcheck Parser Issue

Let me show you quickly with an example, here is how a single collation was returned before:
<response>
<result numFound=”1″ start=”0″>
<doc>
<str name=”Key”>224fbdc1-12df-4520-9fbe-dd91f916eba1</str>
</doc>
</result>
<lst name=”spellcheck”>
<lst name=”suggestions”>
<lst name=”hell”>
<int name=”numFound”>1</int>
<int name=”startOffset”>0</int>
<int name=”endOffset”>4</int>
<arr name=”suggestion”>
<str>dell</str>
</arr>
</lst>
<lst name=”ultrashar”>
<int name=”numFound”>1</int>
<int name=”startOffset”>5</int>
<int name=”endOffset”>14</int>
<arr name=”suggestion”>
<str>ultrasharp</str>
</arr>
</lst>
<str name=”collation”>dell ultrasharp</str>
</lst>
</lst>
</response>

And then with later versions of Solr 4.x multiple collations were returned:

<response>
 <result name="response" numFound="0" start="0"></result>
 <lst name="spellcheck">
 <lst name="suggestions">
 <lst name="produtc">
 <int name="numFound">1</int>
 <int name="startOffset">0</int>
 <int name="endOffset">7</int>
 <arr name="suggestion">
 <str>product</str>
 </arr>
 </lst>
 <lst name="collation">
 <str name="collationQuery">product</str>
 <int name="hits">1000</int>
 <lst name="misspellingsAndCorrections">
 <str name="produtc">product</str>
 </lst>
 </lst>
 </lst>
 </lst>
</response>

The detail was that SolrNet would raise an issue because the numFound node was not found. Well, this issue was fixed now.

This is just the first release that I do on SolrNet since I was granted permission to provide new releases. I am merely getting up to speed to work my way through the backlog of improvements and including support for newer releases of Solr.

If you have any questions, don’t hesitate to contact me via this blog or @xmorera in Twitter.

I have been working with Solr for a while, mainly from the .NET world and I basically love it. I use SolrNet which I think it is a very mature and stable library. I was asked today if I have ever used SolrExpress and if I recommend it over SolrNet.

The short answer is no, I have not used it. Therefore I can’t give a facts based recommendation, but looking over the source code of both libraries it is my opinion that SolrNet is still more complete. So I still believe SolrNet to be a more sensible choice.

It is worth mentioning that is a biased point of view,  as I have used SolrNet multiple times and it really has made my life a lot easier.

Having said that, besides using it several times, I have authored a few things around Solr and SolrNet and used it extensively. It works fine and I know it pretty well. It basically gets the job done, it is pretty mature and almost complete (pending SolrCloud and a few minor things like a breaking change on collation).

Some of the things I created

I created a Solr training for Pluralsight

https://www.pluralsight.com/courses/enterprise-search-using-apache-solr

Getting Started with Enterprise Search Using Apache Solr …
www.pluralsight.com
Search is one of the most misunderstood functionalities in the IT industry. Apache Solr brings high quality Enterprise Search to the masses.

And a SolrNet training for Pluralsight

https://www.pluralsight.com/courses/implementing-search-dotnet-applications

I wrote a book for a company called SyncFusion for their Succinctly Series for Solr and SolrNet

https://www.syncfusion.com/resources/techportal/ebooks/apachesolr

I’ve also done internal trainings, presentations and webcasts on Solr + SolrNet
http://www.meetup.com/Atlanta-Net-User-Group/events/222161640/

Learn How to Add Search to .NET with Solr & SolrNet …
www.meetup.com
Search is a functionality that most people take for granted while at the same time it is deeply misunderstood and usually poorly implemented. .NET

SolrNet does not have yet support for SolrCloud in the main repository, but there is one fork that already uses it but our current project does not use forks, only the main repository. If that is not a blocker for your customer, go ahead or like in our case, just use a load balancer for querying and a call to zookeeper api to get leader for indexing.

Hope this helps.

A couple of days ago I got asked, how do we monitor our cluster? Well, there are professional ways and other for the budget conscious deployment. Here are a few options that came to my mind:

• You have the ping request handler which can be used to determine if a node is up and running – this is useful if you want to configure the load balancer to determine which nodes are responding
• Additionally I’ve seen environments where a monitoring service uses several predefined queries that are issued at a predefined interval and will notify if no response is received. Something like http://www.site24x7.com/ but behind the firewall. I do not know which/if monitoring services you might have.
• And there are more specialized tools, for example Sematext although some of them are more Linux friendly, so it is necessary to look for Windows counterparts if you don’t have Linux.
• Also you can use the clusterstate.json (this would be the one from prod https:///solr/zookeeper?detail=true&path=/clusterstate.json) from Zookeepr which will tell you the state of the nodes. You just need to do a bit of parsing which can be done pretty easily with a bit of Json.Net which is easy to learn.
• And regarding monitoring your cluster’s use in terms of queries done, you can definitively use the Solr logs and analyze queries.

Just a few thoughts I wanted to share.

Many times have I stopped and restarted Solr to reload a core, yes it is kind of a rookie way as you can always go to the Admin UI, Core Admin and reload Core.

But what if you wanted to have a really fast way of reloading your core?

Just do it via the admin handler!
http://{SOLR IP}:{SOLR PORT}/solr/admin/cores?action=RELOAD&core={CORE NAME}

You can even add it to your code and make a simple call or better yet use SolrNet via the admin functionality found below:

https://github.com/mausch/SolrNet/blob/master/Documentation/Core-admin.md

I am preparing for a presentation this month on Solr and SolrNet for the Atlanta .NET User Group.  Solr 5 is already out but I will be running my demos using Solr 4.10. Now that I am starting the preparation process, it really feels so good to know that starting a local Solr is SO EASY. Check out the steps which couldn’t be easier:

– Assuming you already downloaded Solr (here if you haven’t: http://lucene.apache.org/solr/downloads.html)

– Just extract into a folder. Mine is called AtlantaSolr

– Make sure you have Java running. If unsure just type java -version

– Now navigate to your Solr folder, in my case C:\Dropbox\Public Speaking\AtlantaSolrSolrNet

– Type the magic words java -jar start.jar and let it load.

– Voila! Navigate to localhost:8983/solr

It couldn’t be easier!

I am working in a project that sounds like heaven to me. Big company, hundreds of developers, latest technology all around, totally agile and the search is done with Solr and a REST API in C# which of course uses SolrNet (who would think otherwise?)

In any case, spellcheck was enabled and this wreaked havoc whenever servers were rebooted. It seems like SolrCloud has an issue with spellchecking . The problem is that setting spellcheck in /select request handler makes Solr spin its wheels for a long time while starting, and it has been tracked inhttps://issues.apache.org/jira/browse/SOLR-6679. The recommended workaround is to have spell check set up in a different request handler.

But here is the problem. In SolrNet you can’t easily explicitly specify the request handler. It basically uses /select.  The request handler is specified via the Handler property in ISolrQueryExecuter. You can see it in action here:

https://github.com/mausch/SolrNet/blob/master/SolrNet/Impl/SolrQueryExecuter.cs

I checked through many forums and threads to try to get to a solution and here are some of the threads I found:

Changing Handler endpoint in SolrQueryExecuter? https://groups.google.com/forum/?fromgroups=#!searchin/solrnet/handler/solrnet/Kqxn68pU0uo/uG50WSxu_swJ

How can I perform solrnet query in two different request handler? https://groups.google.com/forum/#!topic/solrnet/ZA-bv9dkh_0

Different request handler https://groups.google.com/forum/#!topic/solrnet/SP14XmifcrY

Calling Custom Request Handler https://groups.google.com/forum/#!topic/solrnet/THX-ADS5CLQ

http://stackoverflow.com/questions/13393700/how-we-changes-standard-query-handler

There were many recommendations, among them:

–          Use qt, which the problem is that it is deprecated and I think will not be available in Solr 5. And there is a lot of pushback against qt.

–          Move to CastleWindsor, which is what Eduardo, a friend of mine did last week.  I don’t have enough time to do this. On a really tight schedule.

–          Replace the Handler property in SolrQueryExecuter, which is what was recommended in one of the threads

–          Or Remove() and re Register() the ISolrQueryExecuter

One of the recommendations was modify the Handler this way:

Startup.Init<T>(new SolrConnection("http://localhost:8080/solr"));

var executor = ServiceLocator.Current.GetInstance<ISolrQueryExecuter<T>>() as SolrQueryExecuter<T>;

executor.Handler = "/new";

Which did not work as it did not modify the registered instance. No idea, but if you know how to fix let me know.

So the recommendation from Mauricio Scheffer was to Remove and Reregister, which I did not know how to do but Satish, a very friendly developer, helped me. Here is the solution:

Startup.Init<MyDocument>( “http://localhost:8080/solr”);

var container = ServiceLocator.Current as SolrNet.Utils.Container;

container.Remove<ISolrQueryExecuter<MyDocument>>();

var instance = new SolrQueryExecuter<MyDocument>(container.GetInstance<ISolrAbstractResponseParser<MyDocument>>(), new SolrConnection(“http://localhost:8080/solr”), container.GetInstance<ISolrQuerySerializer>(), container.GetInstance<ISolrFacetQuerySerializer>(), container.GetInstance<ISolrMoreLikeThisHandlerQueryResultsParser<MyDocument>>());

instance.Handler = "/yourhandler";

And this saved my day!